HF rig shuts itself off when tuning dipole on 20 Meters

[KD2DBM]

I believe I know the answer but I wanted to run this by everyone to see if they agree. My HF rig (Kenwood TS-430S) shuts itself off when I go to tune up my dipole (in a closed loop configuration). It never did that before I added an "ugly balun" (6 turns of coax) to the feed point of my 5BTV and changed the power supply from a Radio Schak 25 AMP switching Power supply to an Astron RS-20A power supply. My setup is as follows:

ANTENNAS: 5BTV vertical, 130 Foot off center fed Dipole, In triangle closed loop. BOTH use RG-58U coax. BTV has a ugly Balun at the feed point, the Dipole has a choke inside the shack to help deplete RF in the shack.

RIG: Kenmwood TS-430s

POWERSUPPLY: Astron RS-20A

ANTENNA TUNER: AT-250 AUTO TUNER

GrounDed to 8 foot ground rod with 4 foot legnth of #14 solid wire right out side Shcak Window.

Originally I had no balun at the feed point of the 5BTV and was using the 25AMP switching Power Supply.

NOW, when I goto tune the rig on 20 Meters on the Dipole and give anything over 10 watts power the rig will shut itself off. It  tunes on all the other bands just fine just 20 doesn't seem to like the dipole now.

I believe there might be some kind of ground problem some where, maybe in the Tuner??? Or could it be the powersupply? I switched power supplies due to the fact the Switching supply was causing HUGE amounts of noise, I couldn't even copy ANYONE on 20 meters until I changed to the Astron power supply.

Any thoughts? The BTV vertical works BEAUTIFULLY on all 5 bands It's rated for...Of course I wonder if THAT is not becasue It is mounted on my metal roof??...the metal roof acting as the radial system...lol.

Anyone got any other ideas or am I right on the ground problem???

Thanks,

Bill, KD2DBM

[NO2A]

You could have rf getting into your rig or power supply. Not sure if that power supply can handle the current demand for the `430. The RS-20 is rated at 16 amps continuous,20 intermittant. It might be fine for ssb,but not cw. If you have a dummy load,will the rig put out 100 watts into it? I`d try that first. If the rig shuts down at anything over 10 watts it sounds like rf is causing it. Could also be coax problem,since the rig works fine with the vertical.

[KE3WD]

Does that Astron supply have a three prong grounded AC plug? 

The switching supply can provide total isolation whereas the linear Astron could be creating a ground loop via the third prong ground connection. 

The common three prong AC adaptor can be used on the astron plug to proof that, if you break the ac ground and the problem goes away, there's your answer. 

But not considered entirely safe to leave it that way, if proven via the adaptor, then you must redo your grounds elsewhere such that you keep the "safety" ground at the plug and eliminate the loop from the other grounds. 

73

[WN2C]

The power supply is not big enough...16 amp continuous...20 surge

Rick  wn2c